JP2017009066A - Irregular shape tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an irregular shape pipe enabling breakage of a main pipe and a branch pipe or damage of a fiber reinforced resin layer to be prevented even if a protective concrete layer is not provided, enabling the main pipe and the branch pipe to be surely and easily position set when the irregular shape pipe is manufactured and enabling connection while assuring an effective length of the branch pipe and quality in angle to form a branch.SOLUTION: A main pipe 2a is provided with a communication hole 21 communicated with a branch pipe 3a. When the branch pipe 3a is arranged at a plane facing the periphery of the communication hole 21 with its pipe axis being directed in a horizontal direction, each of a pipe top portion and a pipe bottom portion of the branch pipe 3a is provided with a cutout part 31 in a prescribed angular range, an end surface of the branch pipe 3a serving as a portion becoming a pipe side part of the branch pipe 3a is abutted against a wall surface of the main pipe 2a and set in position, and after filling an elastic body 4a in the cutout part 31, fiber-reinforcing resin is laminated at inner and outer circumferential surfaces of the abutting parts of the main pipe 2a and the branch pipe 3a as a fiber-reinforced resin layer 5 to connect the main pipe 2a and the branch pipe 3a to each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a deformed pipe, and more particularly to a joint structure of a main pipe and a branch pipe.

As shown in FIG. 6, as a deformed pipe 100 in which a branch pipe 102 is provided so as to branch from the main pipe 101, an FRP pipe formed of fiber reinforced resin, or an FRP inner layer on the inner and outer peripheral surfaces of a resin mortar layer Conventionally, an FRPM pipe formed by laminating the outer layer and the FRP outer layer integrally is used as the main pipe 101 or the branch pipe 102.
The deformed tube 100 can be obtained as follows.
That is, first, as shown in FIG. 7, a hole (hereinafter referred to as “communication hole”) 103 for communicating with the branch pipe 102 is formed in the main pipe 101, and the end face of the branch pipe 102 on the main pipe 101 side is formed. The branch pipe 102 is cut along the outer peripheral surface of the main pipe 101.

  Then, as shown in FIG. 8, the branch pipe 102 is butted at the butted portion 104 and at least in the vicinity thereof in a state where the branch pipe 102 is butted so as to be along the peripheral edge of the communication hole 103 of the main pipe 101. The fiber reinforced resin obtained by impregnating the resin into a chopped strand mat made of glass fiber or a roving cloth reinforcing fiber is laminated to a predetermined thickness on the inner and outer peripheral surfaces of the main pipe 101 and the branch pipe 102, and then the impregnated resin is cured. A fiber reinforced resin layer 105 is formed, and the main pipe 101 and the branch pipe 102 are joined in a watertight manner by the fiber reinforced resin layer 105.

By the way, the deformed pipe 100 manufactured in this way is often used by being buried in the underground 200, as shown in FIG. 9, but when it is buried in the underground 200, it is buried in the pipe. In addition to the earth pressure of the return soil acting, a load of a traveling vehicle or the like may be applied.
When receiving the earth pressure or the load of the traveling vehicle or the like, the main pipe 101 swells in the horizontal direction due to the earth pressure or the load applied from above as shown by the chain line in FIGS. It deforms as follows.

As shown in FIG. 9, when the deformed pipe 100 is embedded in the underground 200 so that the central axis of the branch pipe 102 is oriented substantially in the horizontal direction, the main pipe 101 is deformed as described above. As shown in FIG. 10, a large tensile stress is generated in the direction in which the main pipe 101 moves away from the branch pipe 102 on the top side of the branch pipe 102 and the bottom side of the branch pipe 102 of the butting portion 104. On the other hand, the main pipe 101 and the branch pipe 102 are hardly separated from each other at the side of the butt portion 104 on the side of the branch pipe 102, and the generated stress is small.
For this reason, even if the deformation is relatively small, there is a possibility that the deformed pipe 100 may be broken at a portion corresponding to the top of the butt portion 104 on the side of the branch pipe 102 and the bottom of the pipe on the side of the branch pipe, or the fiber reinforced resin layer 105 may be broken. is there.

Therefore, conventionally, in order to prevent such deformation due to deformation of the deformed pipe 100, protective concrete is placed around the deformed pipe 100 to protect the deformed pipe 100.
However, in the construction structure in which such a protective concrete layer is provided, there is a problem in that it takes time to place protective concrete for each deformed pipe 100, time is required for construction, and the construction cost increases.

  On the other hand, as shown in FIG. 11, an elastic body 106 is disposed between the main pipe 101 and the branch pipe 102 to make a butt, and a fiber reinforced resin 105 is laminated and connected to the inner and outer peripheral surfaces of these butt parts. The modified pipe 110 (see, for example, Patent Document 1) and the modified pipe 120 in which the fiber-reinforced resin layer is more difficult to break using the strip-shaped reinforcing sheet 107 as the fiber-reinforced resin are proposed, as shown in FIG. (For example, refer to Patent Document 2).

JP 2000-291864 JP JP 2005-90673 A

However, in the deformed tube 110 of the invention of Patent Document 1, there is a limit to the followability of the elastic body 106 with respect to the deformation of the deformed tube 110, and when a deformation amount exceeding the limit of the elastic body 106 occurs, the fiber reinforced resin The layer part may be damaged. In particular, the larger the diameter of the tube, the larger the deformation amount, so that it tends to break. For this reason, as a safety measure, the periphery of the deformed pipe 110 is still often protected by protective concrete. In addition, a certain gap is secured between the main pipe 101 and the branch pipe 102, and the elastic body 106 is interposed in the gap, and then a fiber reinforced resin layer is laminated. Therefore, it is difficult to position the branch pipe to be branched. .
Therefore, when the fiber reinforced resin layer is laminated on the inner and outer peripheral surfaces of the abutting portion of the main pipe 101 and the branch pipe 102 during manufacturing, the position of the branch pipe 102 and the angle at which the branch pipe 102 is branched change to change the branch pipe 102. There is a problem that the effective length and the branching angle are likely to vary, and it is difficult to ensure the quality of the deformed tube 110.

  Moreover, in the invention of Patent Document 2, the strip-shaped reinforcing fiber sheet 107 is used as the reinforcing fiber material of the fiber reinforced resin layer, and the fiber reinforced resin layer is hardly damaged by devising the winding method. Again, in order to reduce the stress generated in the abutting portion 104 of the main pipe 101 and the branch pipe 102, it is necessary to interpose the elastic body 106 in the abutting portion 104 of the main pipe 101 and the branch pipe 102. Is difficult to position.

  The present invention has been made in view of such problems, and can prevent the breakage of a main pipe or a branch pipe or the breakage of a fiber-reinforced resin layer without providing a protective concrete layer. It is an object of the present invention to provide a deformed pipe that can position the main pipe and the branch pipe reliably and easily, and can be connected while ensuring the quality of the effective length of the branch pipe and the angle of branching.

  In order to achieve the above object, a deformed pipe according to the present invention (hereinafter referred to as a “shaped pipe of the present invention”) includes a main pipe, a branch pipe, a communication hole provided in a wall surface of the main pipe, and a branch pipe. And at least one of the inner peripheral surface side of the branch pipe and the main pipe and the outer peripheral surface side of the branch pipe and the main pipe at least in the butted portion of the main pipe and the branch pipe and in the vicinity thereof Is a deformed pipe in which the main pipe and the branch pipe are joined in a watertight manner, and at least one of the branch pipe side end and the periphery of the communication hole of the main pipe When the tube axis of the branch pipe is oriented in the horizontal direction, the pipe has a notch that forms a gap between the branch pipe and the main pipe at a position that becomes the top and the bottom of the branch pipe, The main pipe is located on the end face of the branch pipe at a position where both side parts of the branch pipe are located. By along the wall surface, the branch pipe is characterized in that it is positioned.

  In the modified pipe of the present invention, the main pipe and the branch pipe are not particularly limited, and examples thereof include an FRPM pipe (fiber reinforced resin mortar pipe), an FRP pipe (fiber reinforced resin pipe), and a rigid polyvinyl chloride pipe.

In the modified pipe of the present invention, the cutout is preferably filled with an elastic body.
That is, when the reinforcing fiber material constituting the fiber reinforced resin is laminated at the butted portion of the main pipe and the branch pipe and in the vicinity thereof, the reinforcing fiber material can be easily laminated without dropping into the notch portion.
And since it has elasticity, the effect of a notch part is not impaired.

The elastic body is not particularly limited as long as it has elasticity that does not impair the operational effects provided with the notches, but for example, unsaturated polyester resin, silicone resin, urethane resin, styrene-butadiene rubber, chloroprene rubber, Various rubbers such as ethylene / propylene rubber and foamed rubber can be employed, and styrene / butadiene rubber, chloroprene rubber, ethylene / propylene rubber and the like are preferable.
The surface of the elastic body is preferably subjected to a surface treatment such as primer application in order to ensure the interface strength with the fiber reinforced resin.

  In the deformed pipe of the present invention, the notch is not particularly limited, but, depending on the diameter, that is, the amount of bending set, when the branch pipe is arranged so that its pipe axis is oriented in the horizontal direction, It is preferable that they are provided from the top and the bottom of the pipe to the left and right, that is, in the range of the central angle 2θ = 40 to 160 °, and more preferably in the range of the central angle 2θ = 60 to 160 °.

Incidentally, if the range in which the notch is provided is less than the central angle 2θ = 40 °, there is a possibility that the effect of preventing the separation between the butted portion of the main pipe and the branch pipe cannot be expected due to the notch.
On the other hand, if the central angle exceeds 2θ = 160 °, there is a possibility that the alignment of the branch pipe at the time of manufacture may be hindered, and the contact area between the branch pipe and the main pipe is too small. When a horizontal displacement occurs in the pipeline and a bending moment acts in the horizontal direction of the branch pipe, the section modulus of the pipe side is insufficient, and one pipe side approaches as viewed from above, while the other There is an increased possibility that the side portion of the tube will be separated and bend into a toroidal shape with respect to the main tube.

The deformed pipe of the present invention is not particularly limited, but it is preferable that the length of the cutout portion in the axial direction of the branch pipe or the length in the radial direction of the communication hole of the main pipe is preferably 5 to 100 mm.
That is, when the length is less than 5 mm, depending on the tube diameter, there is a possibility that the effect of providing the notch portion may not be exhibited. When the length exceeds 100 mm, there is a problem in the bonding strength by the fiber reinforced resin depending on the tube diameter. There is a risk of going out.

Although the deformed pipe of the present invention is not particularly limited, it is preferable that the fiber reinforced resin layer has a structure in which the side near the butted portion of the main pipe and the branch pipe is thick and the side far from the butted portion is thin.
That is, a large force is not applied to the portion far from the butted portion compared to the vicinity of the butted portion. Therefore, by increasing the thickness of the fiber reinforced resin layer near the butt, where a large force is likely to be applied, and by reducing the thickness of the fiber reinforced resin layer on the side far from the butt, where there is little risk of applying a large force. In addition, it is possible to increase the bonding strength of the vicinity portion including the butted portion and the notch portion of the main pipe and the branch pipe to make it more resistant to deformation, and to reduce the overall material cost and manufacturing cost of the fiber reinforced resin layer.

In the deformed pipe of the present invention, the reinforcing fiber material constituting the fiber reinforced resin layer is not particularly limited, but for example, woven fabric mats and sheets of carbon fibers, aramid fibers, glass fibers, bamboo, etc., sheets, tapes, Non-woven mats, chopped strands and the like can be mentioned.
Further, the reinforcing fiber material may be changed according to the place where it is laminated.

For example, the reinforcing fiber material of fiber reinforced resin laminated on the side close to the butt portion of the main pipe and the branch pipe is made of carbon fiber or aramid fiber, and the reinforcing fiber material of fiber reinforced resin laminated on the side far from the butt portion is It is good also as a structure which consists of glass fiber. That is, big force is not added to a part far from a butt | matching part compared with a butt | matching vicinity part. Therefore, only the fiber reinforced resin layer in the portion close to the butt portion, where a large force is likely to be applied, is expensive, but it is superior in strength, but a large force is applied using a carbon fiber or aramid fiber reinforcing fiber material. Cost reduction can be achieved as much as possible by using a glass fiber capable of reducing the cost for the reinforcing fiber material of the fiber reinforced resin layer on the side far from the butt portion where there is little fear.
Of course, since the reinforcing fiber material in the vicinity of the butt portion to which a large force is applied is a carbon fiber or an aramid fiber, sufficient bonding strength can be ensured and deformation can be resisted.

In the deformed tube of the present invention, the matrix resin of the fiber reinforced resin is not particularly limited, and examples thereof include unsaturated polyester resins, epoxy resins, phenol resins,
Unsaturated polyester resins are preferred.

  As described above, the deformed pipe of the present invention is positioned such that the main pipe and the branch pipe communicate with the communication hole provided in the wall surface of the main pipe and the branch pipe, and at least the main pipe and the branch pipe A fiber reinforced resin is laminated along at least one of the inner peripheral surface side of the branch pipe and the main pipe and the outer peripheral surface side of the branch pipe and the main pipe at the butting portion of the main pipe and the main pipe. A deformed pipe joined in a water-tight manner, and when the pipe axis of the branch pipe at least one of the main pipe side end of the branch pipe and the periphery of the communication hole of the main pipe faces in a horizontal direction, The branch pipe is provided with a notch for forming a gap between the branch pipe and the main pipe at the position of the top and the bottom of the branch pipe, and the position of the branch pipe on both sides is the end face of the branch pipe. The branch pipe is positioned by being along the wall surface of the main pipe. Since, without providing a protective concrete layer, it is possible to prevent a breakage of the fracture and fiber-reinforced resin layer of the main pipe and branch pipe. Further, in manufacturing, the main pipe and the branch pipe can be reliably positioned to ensure connection with the effective length of the branch pipe and the quality of the branching angle.

That is, according to this invention, parts other than the notch part of a branch pipe are faced | matched by the outer wall surface of the main pipe, and a branch pipe is correctly positioned in the direction to branch. Therefore, when laminating fiber reinforced resin at the butt section between the main pipe and the branch pipe, the end face position of the main pipe and the branch pipe and the branching angle do not change, and the variation in the effective length of the branch pipe and the branching angle are suppressed. It is possible to manufacture a deformed tube with a set quality.
In addition, when the deformed pipe is buried in the ground, the main pipe part of the deformed pipe bends in the vertical direction due to the action of earth pressure, etc., and when the deformed pipe swells and deforms in the horizontal direction, the branch pipe with the maximum amount of deformation Since the notch part is formed in the part corresponding to the top part and the pipe bottom part of a branch pipe, this notch part eases the distortion which acts on a fiber reinforced resin layer.
Therefore, it is possible to prevent the main pipe and branch pipes from being broken and the fiber reinforced resin from being broken, so that construction of a concrete protective work for protecting the deformed pipe is not required, the cost can be reduced, and the construction period can be shortened. Can do.

1A and 1B show a first embodiment of a deformed pipe of the present invention, in which FIG. 1A is a side view thereof, and FIG. 1B is a front view of a cross section of a central portion of the branch pipe as viewed from the main pipe axis direction. It is process drawing explaining the manufacturing process of the deformed pipe of FIG. 1, Comprising: It is a perspective view which shows the state before joining the main pipe and a branch pipe. It is a perspective view showing the state before joining the main pipe and branch pipe of FIG. 2, and forming a fiber reinforced resin layer. It is principal part sectional drawing of FIG. Sectional drawing explaining the manufacturing process of the deformed pipe of 2nd Embodiment of the deformed pipe of this invention, Comprising: The main pipe and the branch pipe are joined, and sectional drawing showing the state before forming a fiber reinforced resin layer It is. It is a side view which shows the conventional deformed pipe. It is a front view which shows the deformed pipe of FIG. It is process drawing explaining the manufacturing process of the deformed pipe of FIG. 6, Comprising: It is a perspective view which shows the state before joining the main pipe and a branch pipe. It is a front view which shows typically the deformation | transformation by the earth pressure which acts on the conventional deformed pipe. It is a front view which shows typically the deformation | transformation of the butt | matching part of the main pipe and branch pipe by the earth pressure which acts on the conventional deformed pipe. It is a front view explaining the conventional modified pipe improved. It is a side view explaining the conventional modified pipe further improved.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a first embodiment of a deformed tube of the present invention.

As shown in FIG. 1, the deformed pipe 1 a includes a main pipe 2 a, a branch pipe 3 a, an elastic body 4 a, and a fiber reinforced resin layer 5.
The main pipe 2a is obtained by processing an FRPM pipe or an FRP pipe as a raw material pipe, and as shown in FIG. 2, a communication hole 21 is formed at a connection position of the branch pipe 3a.

The branch pipe 3a is a semi-finished product obtained by processing an FRPM pipe or FRP pipe as a raw material pipe so that the end on the main pipe 2a side is formed into a substantially bowl shape in which the end face is in close contact with the peripheral portion of the communication hole 21 ( After forming, a notch 31 is obtained by cutting the semi-finished product as shown in FIG.
The notch 31 is appropriately determined depending on the set deflection amount (depending on the pipe diameter, pipe material, pipe thickness, etc.), but when the branch pipe 3a is installed with the pipe axis oriented in the horizontal direction, As seen from the pipe axis direction of the branch pipe 3a that becomes the top 11 and the pipe bottom 12, as shown in FIG. 1A, the central angle 2θ = 40 to 160 across the line segment connecting the pipe top 11 and the pipe bottom 12. It is formed in a stepped shape with a distance of 5 to 100 mm between the outer arc and the inner arc at a degree of about 60 ° (preferably 60 to 160 °).

And the branch pipe 3a is a pipe side of the branch pipe 3a at the peripheral part of the communication hole 21 of the main pipe 2a when the branch pipe 3a is installed with the pipe axis oriented in the horizontal direction. It is in close contact with the portion corresponding to the portion 13.
That is, an arc-shaped gap is formed between the main pipe 2a and the branch pipe 3a by the notch 31. The elastic body 4a is filled in the notch 31 so as to close the gap.
In addition to the stepped shape, the shape of the notch 31 is the largest at the top and the bottom of the branch pipe and is a shape that is curved in a triangular shape or a substantially elliptical shape that gradually decreases toward the pipe side of the branch pipe. It does not matter.

The elastic body 4a is made of unsaturated polyester resin, silicone resin, urethane resin, various rubbers such as styrene / butadiene rubber, chloroprene rubber, ethylene / propylene rubber, foam rubber, etc., and the branch pipe 3a or It is bonded to the main pipe 2a.
The fiber reinforced resin layer 5 is made of fiber reinforced resin, and is laminated so as to cover the inner and outer peripheral surfaces of the main pipe 2a and the branch pipe 3a. The main pipe 2a and the branch pipe 3a communicate with each other in a watertight manner. And the branch pipe 3a are joined.

The fiber reinforced resin layer 5 includes the branch pipe 3a and the butted surface of the main pipe 2a, and is provided on the inner and outer peripheral surfaces of the branch pipe 3a and the main pipe 2a in the vicinity of the butted surface.
The fiber reinforced resin layer 5 is formed by winding a cloth or a mat of carbon fiber, aramid fiber or glass fiber impregnated with a thermosetting resin such as unsaturated polyester around the inner and outer peripheral surfaces of the branch pipe 3a and the main pipe 2a. After being attached in a predetermined thickness, the thermosetting resin is cured.

  Here, the vicinity means, on the side of the branch pipe 3a, a length portion within 50% of the pipe diameter of the branch pipe 3a from a line segment connecting the top and bottom of the outer peripheral surface of the main pipe 2a. On the side, it means a length portion within 50% of the diameter of the main pipe 2a from the inner peripheral edge of the communication hole 21 of the main pipe 2a to the main pipe 2a side.

As described above, when the branch pipe 3a is disposed so that the pipe axis of the branch pipe 3a faces the horizontal direction, the deformed pipe 1a has a central angle 2θ = Since the cutout portion 31 of 40 to 160 ° is provided, the cutout portion 31 relaxes strain acting on the fiber reinforced resin layer 5.
Therefore, it is possible to prevent the main pipe 2a and the branch pipe 3a from being broken and the fiber reinforced resin layer 5 from being broken, and the construction of a concrete protective work for protecting the deformed pipe 1a becomes unnecessary, and the cost can be reduced. The construction period can be shortened.

Moreover, since the end surface of the portion that becomes the tube side portion of the branch pipe 3a is formed along the outer peripheral surface of the portion that becomes the tube side portion of the main tube 2a, the end surface of the portion that becomes the tube side portion of the branch tube 3a Is closely attached to the outer wall surface of the main pipe 2a, so that the branch pipe 3a can be reliably positioned to ensure the effective length of the branch pipe and the quality of the branching angle.
And without a protective concrete layer. The main pipe 2a and the branch pipe 3a can be prevented from being broken and the fiber reinforced resin layer can be prevented from being broken, and the main pipe 2a and the branch pipe 3a can be reliably positioned for manufacturing, and the branch pipe has an effective length and an angle quality for branching. Can be secured and connected.

That is, according to the present invention, the end surface of the portion other than the notch 31, that is, the portion that becomes the tube side when the tube axis of the branch tube 3 a faces the horizontal direction is in surface contact with the outer wall surface of the main tube 2 a. It is faced to do. Therefore, since the branch pipe 3a is positioned in the direction in which it is desired to branch, for example, when the fiber reinforced resin forming the fiber reinforced resin layer is wound and laminated while rotating the main pipe 2a, the butt surface is always in a fixed position. For this reason, the angle at which the branch pipe 3a branches from the main pipe 2a and the effective length do not change.
Therefore, it is possible to easily and accurately manufacture the deformed pipe 1a with good quality without causing variations in the branching angle and effective length of the branch pipe 3a.

Further, when the deformed pipe 1a is buried in the ground, earth pressure or the like acts to cause the main pipe portion of the deformed pipe to bend in the vertical direction and swell and deform in the horizontal direction, so that the branch pipe 3a has the maximum deformation amount. Since the notch 31 is formed in the portion corresponding to the tube top and the tube bottom of the branch pipe 3 a, the notch 31 reduces the strain acting on the fiber reinforced resin layer 5.
Therefore, it is possible to prevent the main pipe 2a and the branch pipe 3a from being broken and the fiber reinforced resin layer 5 from being broken, and the construction of a concrete protective work for protecting the deformed pipe 1a becomes unnecessary, and the cost can be reduced. The construction period can be shortened.

  Further, the deformed pipe 1a is supported so that the end face of the pipe side portion of the branch pipe 3a and the main pipe 2a are brought into contact with each other so that the main pipe 2a and the branch pipe 3a maintain a branch angle. Even when a horizontal variation occurs in the pipeline on the side of the branch pipe 3a due to seismic motion or the like when it is buried in the ground, a gap is formed between the end surfaces of the main pipe 2a and the branch pipe 3a, and the entire gap Compared to the case where an elastic body is interposed over the circumference, there is no possibility that one pipe side part approaches and the other pipe side part is separated and bent into a toroidal shape with respect to the main pipe 2a as viewed from above. Is.

  In addition, since the cutout 31 is filled with the elastic body 4a, when the fiber reinforced resin is laminated at the butted portion of the main pipe and the branch pipe and in the vicinity thereof, it is easily laminated without dropping the reinforcing fiber into the cutout. Can do.

FIG. 5 shows a second embodiment of the deformed pipe of the present invention.
As shown in FIG. 5, the deformed pipe 1b is provided with a notch 31 similar to the notch 31 of the deformed pipe 1a only at either the top or the bottom of the branch pipe 3b. .

And the notch part 22 which has the same center angle as the notch part 31 of the branch pipe 3b is provided in either the pipe bottom of the peripheral part of the communication hole 21 of the main pipe 2b, or the part corresponding to the pipe top.
Further, the main pipe 2b and the branch pipe 3b are arranged such that the cutout portion 22 of the main pipe 2b is arranged on the pipe top (pipe bottom) side and the cutout section 31 of the branch pipe 3b is arranged on the pipe bottom (pipe top) side. And the branch pipe 3b are aligned, the cutout portion 22 is filled with the elastic body 4b, and the cutout portion 31 is filled with the elastic body 4a, and then the fiber reinforced resin layer 5 is laminated.

The present invention is not limited to the above embodiment. For example, in the above embodiment, there is one branch pipe 3a, but two or more branch pipes 3a may be provided.
Further, the cutout portion may not be provided on the side of the branch pipe but may be provided in a portion corresponding to the top and bottom of the branch pipe of the communication hole of the main pipe.

  Next, a specific example of the deformed pipe 1a exemplified above will be described.

Example 1
An FRPM pipe having a diameter of 600 mm was used as the main pipe 2a, a hard polyvinyl chloride pipe having a diameter of 300 mm was used as the branch pipe 3a, and a communication hole 21 was formed so that the branch pipe 3a communicated with the main pipe 2a.
Next, the end surface of the branch pipe 3a is cut into a shape that follows the periphery of the communication hole 21 of the main pipe 2a, and then the branch pipe with the line connecting the top and the bottom of the branch pipe 3a as the center. A stepped notch 4 was formed by cutting from the end face of 3a over a depth of 20 mm in the tube axis direction and a central angle 2θ = 160 °.

Next, the elastic body 5 made of styrene / butadiene rubber was filled in the gap formed by the notch 31 in a state where the main pipe 2a and the branch pipe 3a were in contact with each other. In addition, the primary process was performed on the surface of the elastic body 4a in order to ensure the interface adhesive strength with the unsaturated polyester resin mentioned later.
A glass fiber mat and a glass roving cloth (inner circumference) as reinforcing fibers in which the outer peripheral surface and the inner peripheral surface of the main pipe 2a and the branch pipe 3a are impregnated with an unsaturated polyester resin at the butted surfaces of the main pipe 2a and the branch pipe 3a and the vicinity thereof. After laminating the surface thickness of 5 mm and the outer peripheral surface thickness of 8 mm), the unsaturated polyester resin was cured, and the main pipe 2a and the branch pipe 3a were joined by the fiber reinforced resin layer 5 to obtain the deformed pipe 1. .

(Example 2)
A deformed pipe 1 was obtained in the same manner as in Example 2 except that an FRPM pipe having a diameter of 1800 mm was used as the main pipe 2a and an FRPM pipe having a diameter of 900 mm was used as the branch pipe 3a.

(Comparative Example 1)
A deformed pipe was obtained in the same manner as in Example 1 except that the notch portion was not provided and the end surface of the branch pipe 3a was directly brought into close contact with the periphery of the communication hole 21 of the main pipe 2a.

  For each of the deformed pipes obtained in Example 1 and Comparative Example 1, with the branch pipes arranged so that the pipe axis is in the horizontal direction, the main pipe is sandwiched from above and below with a jig and vertically The main pipe was bent under a load, and the presence or absence of breakage was examined. The results are shown in Table 1 below.

  From Table 1 above, it can be seen that the deformed pipe of the present invention has excellent strength at the connection between the main pipe and the branch pipe.

1a, 1b Deformed tube 2a. 2b Main pipe 21 Communication hole 22 Notch 3a, 3b Branch pipe 31 Notch 4a, 4b Elastic body 5 Fiber reinforced resin layer

Claims (4)

  The main pipe and the branch pipe are positioned so that the communication hole provided in the wall surface of the main pipe and the branch pipe communicate with each other, and at least in the butted portion of the main pipe and the branch pipe and in the vicinity thereof, the branch pipe and the main pipe A fiber reinforced resin is laminated along at least one of the inner peripheral surface side and the outer peripheral surface side of the branch pipe and the main pipe, and the main pipe and the branch pipe are water-tightly joined, At least one of the main pipe side end of the branch pipe and the periphery of the communication hole of the main pipe at a position that becomes the top and bottom of the branch pipe when the pipe axis of the branch pipe faces in the horizontal direction. The branch pipe is provided with a notch for forming a gap between the branch pipe and the main pipe, and the positions of both side pipes of the branch pipe are along the wall surface of the main pipe at the end face of the branch pipe. A deformed tube characterized in that is positioned.   The deformed pipe according to claim 1, wherein the cutout portion is filled with an elastic body.   The deformed pipe according to claim 1 or 2, wherein the fiber reinforced resin layer is formed so that a side near the butted portion of the main pipe and the branch pipe is thick and a side far from the butted portion is thin.   The cutout portion is provided in a range of a central angle 2θ = 40 to 160 ° across a line segment connecting the top and the bottom of the tube in a plan view as viewed from the central axis direction of the branch pipe. The deformed tube according to any one of the above.